/*
  grob.cc -- implement Grob

  source file of the GNU LilyPond music typesetter

  (c) 1997--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>
*/

#include "grob.hh"

#include <cstring>
#include <math.h>

#include "main.hh"
#include "input-smob.hh"
#include "warn.hh"
#include "pointer-group-interface.hh"
#include "misc.hh"
#include "paper-score.hh"
#include "stencil.hh"
#include "warn.hh"
#include "system.hh"
#include "item.hh"
#include "stencil.hh"
#include "misc.hh"
#include "music.hh"
#include "item.hh"
#include "paper-score.hh"
#include "ly-smobs.icc"
#include "output-def.hh"

Grob *
Grob::clone (int count) const
{
  return new Grob (*this, count);
}

/* TODO:

- remove dynamic_cast<Spanner, Item> and put this code into respective
subclass.  */

#define HASH_SIZE 3
#define INFINITY_MSG "Infinity or NaN encountered"

Grob::Grob (SCM basicprops,
	    Object_key const *key)
{
  key_ = key;
  /* FIXME: default should be no callback.  */
  self_scm_ = SCM_EOL;
  pscore_ = 0;
  status_ = 0;
  original_ = 0;
  interfaces_ = SCM_EOL;
  immutable_property_alist_ = basicprops;
  mutable_property_alist_ = SCM_EOL;
  object_alist_ = SCM_EOL;

  
  /* We do smobify_self () as the first step.  Since the object lives
     on the heap, none of its SCM variables are protected from
     GC. After smobify_self (), they are.  */
  smobify_self ();

  /*
    We always get a new key object for a new grob.
  */
  if (key_)
    scm_gc_unprotect_object (key_->self_scm ());
  SCM meta = get_property ("meta");
  if (scm_is_pair (meta))
    {
      interfaces_ = scm_cdr (scm_assoc (ly_symbol2scm ("interfaces"), meta));
    }

  /* TODO:

  - destill this into a function, so we can re-init the immutable
  properties with a new BASICPROPS value after
  creation. Convenient eg. when using \override with
  StaffSymbol.  */

  char const *onames[] = {"X-offset-callbacks", "Y-offset-callbacks"};
  char const *xnames[] = {"X-extent", "Y-extent"};
  char const *enames[] = {"X-extent-callback", "Y-extent-callback"};

  for (int a = X_AXIS; a <= Y_AXIS; a++)
    {
      SCM l = get_property (onames[a]);

      if (scm_ilength (l) >= 0)
	{
	  dim_cache_[a].offset_callbacks_ = l;
	  dim_cache_[a].offsets_left_ = scm_ilength (l);
	}
      else
	programming_error ("[XY]-offset-callbacks must be a list");

      SCM cb = get_property (enames[a]);
      if (cb == SCM_BOOL_F)
	{
	  dim_cache_[a].dimension_ = SCM_BOOL_F;
	}

      SCM xt = get_property (xnames[a]);
      if (is_number_pair (xt))
	{
	  dim_cache_[a].dimension_ = xt;
	}
      else if (ly_is_procedure (cb))
	{
	  dim_cache_[a].dimension_callback_ = cb;
	}
      else if (cb == SCM_EOL
	       && ly_is_procedure (get_property ("print-function")))
	dim_cache_[a].dimension_callback_ = stencil_extent_proc;
    }
}

Grob::Grob (Grob const &s, int copy_index)
  : dim_cache_ (s.dim_cache_)
{
  key_ = (use_object_keys) ? new Copied_key (s.key_, copy_index) : 0;
  original_ = (Grob *) & s;
  self_scm_ = SCM_EOL;

  immutable_property_alist_ = s.immutable_property_alist_;
  mutable_property_alist_ = ly_deep_copy (s.mutable_property_alist_);
  interfaces_ = s.interfaces_;
  object_alist_ = SCM_EOL;
  
  /* No properties are copied.  That is the job of
     handle_broken_dependencies.  */
  status_ = s.status_;
  pscore_ = 0;

  smobify_self ();
  if (key_)
    scm_gc_unprotect_object (key_->self_scm ());
}

Grob::~Grob ()
{
}

MAKE_SCHEME_CALLBACK (Grob, stencil_extent, 2);
SCM
Grob::stencil_extent (SCM element_smob, SCM scm_axis)
{
  Grob *s = unsmob_grob (element_smob);
  Axis a = (Axis) scm_to_int (scm_axis);

  Stencil *m = s->get_stencil ();
  Interval e;
  if (m)
    e = m->extent (a);
  return ly_interval2scm (e);
}

Interval
robust_relative_extent (Grob *me, Grob *refp, Axis a)
{
  Interval ext = me->extent (refp, a);
  if (ext.is_empty ())
    {
      ext.add_point (me->relative_coordinate (refp, a));
    }

  return ext;
}

Output_def *
Grob::get_layout () const
{
  return pscore_ ? pscore_->layout () : 0;
}

/* Recursively track all dependencies of this Grob.  The status_ field
   is used as a mark-field.  It is marked with BUSY during execution
   of this function, and marked with FINAL when finished.

   FUNCPTR is the function to call to update this element.  */
void
Grob::calculate_dependencies (int final, int busy, SCM funcname)
{
  if (status_ >= final)
    return;

  if (status_ == busy)
    {
      programming_error ("element is busy, come back later");
      return;
    }

  status_ = busy;

  extract_grob_set (this, "dependencies", deps);
  for (int i = 0; i < deps.size (); i++)
    deps[i]->calculate_dependencies (final, busy, funcname);

  SCM proc = internal_get_property (funcname);
  if (ly_is_procedure (proc))
    scm_call_1 (proc, this->self_scm ());

  status_ = final;
}

Stencil *
Grob::get_stencil () const
{
  if (!is_live ())
    return 0;

  SCM stil = get_property ("stencil");
  if (unsmob_stencil (stil))
    return unsmob_stencil (stil);

  stil = get_uncached_stencil ();
  if (is_live ())
    {
      Grob *me = (Grob *) this;
      me->set_property ("stencil", stil);
    }

  return unsmob_stencil (stil);
}

SCM
Grob::get_uncached_stencil () const
{
  SCM proc = get_property ("print-function");

  SCM stil = SCM_EOL;
  if (ly_is_procedure (proc))
    stil = scm_apply_0 (proc, scm_list_n (this->self_scm (), SCM_UNDEFINED));

  if (Stencil *m = unsmob_stencil (stil))
    {
      if (to_boolean (get_property ("transparent")))
	stil = Stencil (m->extent_box (), SCM_EOL).smobbed_copy ();
      else
	{
	  SCM expr = m->expr ();
	  if (point_and_click_global)
	    expr = scm_list_3 (ly_symbol2scm ("grob-cause"), self_scm (), expr);
	  
	  stil = Stencil (m->extent_box (), expr).smobbed_copy ();
	}

      /* color support... see interpret_stencil_expression () for more... */
      SCM color = get_property ("color");
      if (color != SCM_EOL)
	{
	  m = unsmob_stencil (stil);
	  SCM expr = scm_list_3 (ly_symbol2scm ("color"),
				 color,
				 m->expr ());

	  stil = Stencil (m->extent_box (), expr).smobbed_copy ();
	}
    }

  return stil;
}

/*
  VIRTUAL STUBS
*/
void
Grob::do_break_processing ()
{
}

System *
Grob::get_system () const
{
  return 0;
}

void
Grob::add_dependency (Grob *e)
{
  if (e)
    Pointer_group_interface::add_grob (this, ly_symbol2scm ("dependencies"), e);
  else
    programming_error ("null dependency added");
}

void
Grob::handle_broken_dependencies ()
{
  Spanner *sp = dynamic_cast<Spanner *> (this);
  if (original_ && sp)
    return;

  if (sp)
    /* THIS, SP is the original spanner.  We use a special function
       because some Spanners have enormously long lists in their
       properties, and a special function fixes FOO  */
    {
      for (SCM s = object_alist_; scm_is_pair (s); s = scm_cdr (s))
	sp->substitute_one_mutable_property (scm_caar (s), scm_cdar (s));

    }
  System *system = get_system ();

  if (is_live ()
      && system
      && common_refpoint (system, X_AXIS)
      && common_refpoint (system, Y_AXIS))
    substitute_object_links (system->self_scm (), object_alist_);
  else if (dynamic_cast<System *> (this))
    substitute_object_links (SCM_UNDEFINED, object_alist_);
  else
    /* THIS element is `invalid'; it has been removed from all
       dependencies, so let's junk the element itself.

       Do not do this for System, since that would remove references
       to the originals of score-grobs, which get then GC'd (a bad
       thing).  */
    suicide ();
}

/* Note that we still want references to this element to be
   rearranged, and not silently thrown away, so we keep pointers like
   {broken_into_{drul, array}, original}
*/
void
Grob::suicide ()
{
  if (!is_live ())
    return;

  mutable_property_alist_ = SCM_EOL;
  object_alist_ = SCM_EOL;
  immutable_property_alist_ = SCM_EOL;
  interfaces_ = SCM_EOL;
  
  set_extent (SCM_EOL, Y_AXIS);
  set_extent (SCM_EOL, X_AXIS);

  set_extent_callback (SCM_EOL, Y_AXIS);
  set_extent_callback (SCM_EOL, X_AXIS);

  for (int a = X_AXIS; a <= Y_AXIS; a++)
    {
      dim_cache_[a].offset_callbacks_ = SCM_EOL;
      dim_cache_[a].offsets_left_ = 0;
    }
}

void
Grob::handle_prebroken_dependencies ()
{
  /* Don't do this in the derived method, since we want to keep access to
     object_alist_ centralized.  */
  if (original_)
    {
      Item *it = dynamic_cast<Item *> (this);
      substitute_object_links (scm_int2num (it->break_status_dir ()),
			       original_->object_alist_);
    }
}

Grob *
Grob::find_broken_piece (System *) const
{
  return 0;
}

/* Translate in one direction.  */
void
Grob::translate_axis (Real y, Axis a)
{
  if (isinf (y) || isnan (y))
    programming_error (_ (INFINITY_MSG));
  else
    dim_cache_[a].offset_ += y;
}

/* Find the offset relative to D.  If D equals THIS, then it is 0.
   Otherwise, it recursively defd as

   OFFSET_ + PARENT_L_->relative_coordinate (D) */
Real
Grob::relative_coordinate (Grob const *refp, Axis a) const
{
  if (refp == this)
    return 0.0;

  /* We catch PARENT_L_ == nil case with this, but we crash if we did
     not ask for the absolute coordinate (ie. REFP == nil.)  */
  if (refp == dim_cache_[a].parent_)
    return get_offset (a);

  return get_offset (a) + dim_cache_[a].parent_->relative_coordinate (refp, a);
}

/* Invoke callbacks to get offset relative to parent.  */
Real
Grob::get_offset (Axis a) const
{
  Grob *me = (Grob *) this;
  while (dim_cache_[a].offsets_left_)
    {
      int l = --me->dim_cache_[a].offsets_left_;
      SCM cb = scm_list_ref (dim_cache_[a].offset_callbacks_, scm_int2num (l));
      SCM retval = scm_call_2 (cb, self_scm (), scm_int2num (a));

      Real r = scm_to_double (retval);
      if (isinf (r) || isnan (r))
	{
	  programming_error (INFINITY_MSG);
	  r = 0.0;
	}
      me->dim_cache_[a].offset_ += r;
    }
  return dim_cache_[a].offset_;
}

bool
Grob::is_empty (Axis a) const
{
  return !(scm_is_pair (dim_cache_[a].dimension_)
	   || ly_is_procedure (dim_cache_[a].dimension_callback_));
}

void
Grob::flush_extent_cache (Axis axis)
{
  Dimension_cache *d = &dim_cache_[axis];
  if (ly_is_procedure (d->dimension_callback_)
      && scm_is_pair (d->dimension_))
    {
      d->dimension_ = SCM_EOL;

      if (get_parent (axis))
	get_parent (axis)->flush_extent_cache (axis);
    }
}

Interval
Grob::extent (Grob *refp, Axis a) const
{
  Real x = relative_coordinate (refp, a);

  Dimension_cache *d = (Dimension_cache *) & dim_cache_[a];
  Interval ext;

  SCM dimpair = d->dimension_;
  if (scm_is_pair (dimpair))
    ;
  else if (ly_is_procedure (d->dimension_callback_)
	   && d->dimension_ == SCM_EOL)
    d->dimension_ = scm_call_2 (d->dimension_callback_, self_scm (), scm_int2num (a));
  else
    return ext;

  if (!scm_is_pair (d->dimension_))
    return ext;

  ext = ly_scm2interval (d->dimension_);

  SCM extra = get_property (a == X_AXIS
			    ? "extra-X-extent"
			    : "extra-Y-extent");

  /* Signs ?  */
  if (scm_is_pair (extra))
    {
      ext[BIGGER] += scm_to_double (scm_cdr (extra));
      ext[SMALLER] += scm_to_double (scm_car (extra));
    }

  extra = get_property (a == X_AXIS
			? "minimum-X-extent"
			: "minimum-Y-extent");
  if (scm_is_pair (extra))
    ext.unite (Interval (scm_to_double (scm_car (extra)),
			 scm_to_double (scm_cdr (extra))));

  ext.translate (x);

  return ext;
}

/* Find the group-element which has both #this# and #s#  */
Grob *
Grob::common_refpoint (Grob const *s, Axis a) const
{
  /* I don't like the quadratic aspect of this code, but I see no
     other way.  The largest chain of parents might be 10 high or so,
     so it shouldn't be a real issue.  */
  for (Grob const *c = this; c; c = c->dim_cache_[a].parent_)
    for (Grob const *d = s; d; d = d->dim_cache_[a].parent_)
      if (d == c)
	return (Grob *) d;

  return 0;
}

Grob *
common_refpoint_of_list (SCM elist, Grob *common, Axis a)
{
  for (; scm_is_pair (elist); elist = scm_cdr (elist))
    if (Grob *s = unsmob_grob (scm_car (elist)))
      {
	if (common)
	  common = common->common_refpoint (s, a);
	else
	  common = s;
      }

  return common;
}

Grob *
common_refpoint_of_array (Link_array<Grob> const &arr, Grob *common, Axis a)
{
  for (int i = arr.size (); i--;)
    if (Grob *s = arr[i])
      {
	if (common)
	  common = common->common_refpoint (s, a);
	else
	  common = s;
      }

  return common;
}

String
Grob::name () const
{
  SCM meta = get_property ("meta");
  SCM nm = scm_assoc (ly_symbol2scm ("name"), meta);
  nm = (scm_is_pair (nm)) ? scm_cdr (nm) : SCM_EOL;
  return scm_is_symbol (nm) ? ly_symbol2string (nm) : classname (this);
}

void
Grob::add_offset_callback (SCM cb, Axis a)
{
  if (!has_offset_callback (cb, a))
    {
      dim_cache_[a].offset_callbacks_
	= scm_cons (cb, dim_cache_[a].offset_callbacks_);
      dim_cache_[a].offsets_left_++;
    }
}

bool
Grob::has_extent_callback (SCM cb, Axis a) const
{
  return scm_equal_p (cb, dim_cache_[a].dimension_callback_) == SCM_BOOL_T;
}

bool
Grob::has_offset_callback (SCM cb, Axis a) const
{
  return scm_c_memq (cb, dim_cache_[a].offset_callbacks_) != SCM_BOOL_F;
}

void
Grob::set_extent (SCM dc, Axis a)
{
  dim_cache_[a].dimension_ = dc;
}

void
Grob::set_extent_callback (SCM dc, Axis a)
{
  dim_cache_[a].dimension_callback_ = dc;
}

void
Grob::set_parent (Grob *g, Axis a)
{
  dim_cache_[a].parent_ = g;
}

void
Grob::fixup_refpoint ()
{
  for (int a = X_AXIS; a < NO_AXES; a++)
    {
      Axis ax = (Axis)a;
      Grob *parent = get_parent (ax);

      if (!parent)
	continue;

      if (parent->get_system () != get_system () && get_system ())
	{
	  Grob *newparent = parent->find_broken_piece (get_system ());
	  set_parent (newparent, ax);
	}

      if (Item *i = dynamic_cast<Item *> (this))
	{
	  Item *parenti = dynamic_cast<Item *> (parent);

	  if (parenti && i)
	    {
	      Direction my_dir = i->break_status_dir ();
	      if (my_dir != parenti->break_status_dir ())
		{
		  Item *newparent = parenti->find_prebroken_piece (my_dir);
		  set_parent (newparent, ax);
		}
	    }
	}
    }
}

void
Grob::warning (String s) const
{
  SCM cause = self_scm ();
  while (Grob *g = unsmob_grob (cause))
    cause = g->get_property ("cause");

  if (Music *m = unsmob_music (cause))
    m->origin ()->warning (s);
  else
    ::warning (s);
}

void
Grob::programming_error (String s) const
{
  s = _f ("programming error: %s", s);
  message (s);
}
void
Grob::discretionary_processing ()
{
  
}

bool
Grob::internal_has_interface (SCM k)
{
  return scm_c_memq (k, interfaces_) != SCM_BOOL_F;
}

Grob *
Grob::get_parent (Axis a) const
{
  return dim_cache_[a].parent_;
}

/** Return Array of Grobs in SCM list LST */
Link_array<Grob>
ly_scm2grobs (SCM lst)
{
  Link_array<Grob> arr;

  for (SCM s = lst; scm_is_pair (s); s = scm_cdr (s))
    {
      SCM e = scm_car (s);
      arr.push (unsmob_grob (e));
    }

  arr.reverse ();
  return arr;
}

Object_key const *
Grob::get_key () const
{
  return key_;
}

/** Return SCM list of Grob array A */
SCM
ly_grobs2scm (Link_array<Grob> a)
{
  SCM s = SCM_EOL;
  for (int i = a.size (); i; i--)
    s = scm_cons (a[i - 1]->self_scm (), s);

  return s;
}

ADD_INTERFACE (Grob, "grob-interface",
	       "A grob represents a piece of music notation\n"
	       "\n"
	       "All grobs have an X and Y-position on the page.  These X and Y positions\n"
	       "are stored in a relative format, so they can easily be combined by\n"
	       "stacking them, hanging one grob to the side of another, and coupling\n"
	       "them into a grouping objects.\n"
	       "\n"
	       "Each grob has a reference point (a.k.a.  parent): the position of a grob\n"
	       "is stored relative to that reference point. For example the X-reference\n"
	       "point of a staccato dot usually is the note head that it applies\n"
	       "to. When the note head is moved, the staccato dot moves along\n"
	       "automatically.\n"
	       "\n"
	       "A grob is often associated with a symbol, but some grobs do not print\n"
	       "any symbols. They take care of grouping objects. For example, there is a\n"
	       "separate grob that stacks staves vertically. The @ref{NoteCollision}\n"
	       "is also an abstract grob: it only moves around chords, but doesn't print\n"
	       "anything.\n"
	       "\n"
	       "Grobs have a properties: Scheme variables, that can be read and set. "
	       "They have two types. Immutable variables "
	       "define the default style and behavior.  They are shared between  many objects. "
	       "They can be changed using @code{\\override} and @code{\\revert}. "
	       "\n\n"
	       "Mutable properties are variables that are specific to one grob. Typically, "
	       "lists of other objects, or results from computations are stored in"
	       "mutable properties: every call to set-grob-property (or its C++ equivalent) "
	       "sets a mutable property. ",
	       "X-offset-callbacks Y-offset-callbacks X-extent-callback stencil cause "
	       "Y-extent-callback print-function extra-offset spacing-procedure "
	       "context staff-symbol interfaces dependencies X-extent Y-extent extra-X-extent "
	       "meta layer before-line-breaking-callback "
	       "color "
	       "axis-group-parent-X "
	       "axis-group-parent-Y "
	       "after-line-breaking-callback extra-Y-extent minimum-X-extent "
	       "minimum-Y-extent transparent");

